Malnutrition is an important determinant of outcome in patients on dialysis. Its cause is multifactorial and its detection is important when patients embark on dialysis. In this study, we used various indices to assess the prevalence of malnutrition as reflected in protein intake, anthropometric effect, and serum protein level. To avoid the effect that dialysis has on malnutrition, we studied 37 patients who had just started continuous ambulatory peritoneal dialysis (CAPD). Of these new patients, 42% had a residual urea clearance below 1.0 mL/min. In 51% of the patients, serum albumin level was below 33 g/L; in 14%, body mass index was below 19; and in 39%, dietary protein intake was below 0.8 g per kilogram of body weight per day. A total of 76% of our patients had at least one of these three indices. In 8% of the patients, lean body mass was below 60%. We conclude that protein malnutrition is a significant problem in our patients starting CAPD. Dialysis-dependent factors were not implicated, as the patients were studied at the start of dialysis. Low intake of protein was a major problem and may have contributed significantly to malnutrition. The low residual urea clearance implied that dialysis was started relatively late and may have contributed to the low protein intake.